445 lines
9.8 KiB
C
445 lines
9.8 KiB
C
|
/*
|
||
|
|
* Copyright (C) 2005-2008 Red Hat, Inc. All rights reserved.
|
||
|
|
*
|
||
|
|
* This copyrighted material is made available to anyone wishing to use,
|
||
|
|
* modify, copy, or redistribute it subject to the terms and conditions
|
||
|
|
* of the GNU General Public License version 2.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <linux/fs.h>
|
||
|
|
#include <linux/miscdevice.h>
|
||
|
|
#include <linux/poll.h>
|
||
|
|
#include <linux/dlm.h>
|
||
|
|
#include <linux/dlm_plock.h>
|
||
|
|
|
||
|
|
#include "dlm_internal.h"
|
||
|
|
#include "lockspace.h"
|
||
|
|
|
||
|
|
static spinlock_t ops_lock;
|
||
|
|
static struct list_head send_list;
|
||
|
|
static struct list_head recv_list;
|
||
|
|
static wait_queue_head_t send_wq;
|
||
|
|
static wait_queue_head_t recv_wq;
|
||
|
|
|
||
|
|
struct plock_op {
|
||
|
|
struct list_head list;
|
||
|
|
int done;
|
||
|
|
struct dlm_plock_info info;
|
||
|
|
};
|
||
|
|
|
||
|
|
struct plock_xop {
|
||
|
|
struct plock_op xop;
|
||
|
|
void *callback;
|
||
|
|
void *fl;
|
||
|
|
void *file;
|
||
|
|
struct file_lock flc;
|
||
|
|
};
|
||
|
|
|
||
|
|
|
||
|
|
static inline void set_version(struct dlm_plock_info *info)
|
||
|
|
{
|
||
|
|
info->version[0] = DLM_PLOCK_VERSION_MAJOR;
|
||
|
|
info->version[1] = DLM_PLOCK_VERSION_MINOR;
|
||
|
|
info->version[2] = DLM_PLOCK_VERSION_PATCH;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int check_version(struct dlm_plock_info *info)
|
||
|
|
{
|
||
|
|
if ((DLM_PLOCK_VERSION_MAJOR != info->version[0]) ||
|
||
|
|
(DLM_PLOCK_VERSION_MINOR < info->version[1])) {
|
||
|
|
log_print("plock device version mismatch: "
|
||
|
|
"kernel (%u.%u.%u), user (%u.%u.%u)",
|
||
|
|
DLM_PLOCK_VERSION_MAJOR,
|
||
|
|
DLM_PLOCK_VERSION_MINOR,
|
||
|
|
DLM_PLOCK_VERSION_PATCH,
|
||
|
|
info->version[0],
|
||
|
|
info->version[1],
|
||
|
|
info->version[2]);
|
||
|
|
return -EINVAL;
|
||
|
|
}
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static void send_op(struct plock_op *op)
|
||
|
|
{
|
||
|
|
set_version(&op->info);
|
||
|
|
INIT_LIST_HEAD(&op->list);
|
||
|
|
spin_lock(&ops_lock);
|
||
|
|
list_add_tail(&op->list, &send_list);
|
||
|
|
spin_unlock(&ops_lock);
|
||
|
|
wake_up(&send_wq);
|
||
|
|
}
|
||
|
|
|
||
|
|
int dlm_posix_lock(dlm_lockspace_t *lockspace, u64 number, struct file *file,
|
||
|
|
int cmd, struct file_lock *fl)
|
||
|
|
{
|
||
|
|
struct dlm_ls *ls;
|
||
|
|
struct plock_op *op;
|
||
|
|
struct plock_xop *xop;
|
||
|
|
int rv;
|
||
|
|
|
||
|
|
ls = dlm_find_lockspace_local(lockspace);
|
||
|
|
if (!ls)
|
||
|
|
return -EINVAL;
|
||
|
|
|
||
|
|
xop = kzalloc(sizeof(*xop), GFP_KERNEL);
|
||
|
|
if (!xop) {
|
||
|
|
rv = -ENOMEM;
|
||
|
|
goto out;
|
||
|
|
}
|
||
|
|
|
||
|
|
op = &xop->xop;
|
||
|
|
op->info.optype = DLM_PLOCK_OP_LOCK;
|
||
|
|
op->info.pid = fl->fl_pid;
|
||
|
|
op->info.ex = (fl->fl_type == F_WRLCK);
|
||
|
|
op->info.wait = IS_SETLKW(cmd);
|
||
|
|
op->info.fsid = ls->ls_global_id;
|
||
|
|
op->info.number = number;
|
||
|
|
op->info.start = fl->fl_start;
|
||
|
|
op->info.end = fl->fl_end;
|
||
|
|
if (fl->fl_lmops && fl->fl_lmops->fl_grant) {
|
||
|
|
/* fl_owner is lockd which doesn't distinguish
|
||
|
|
processes on the nfs client */
|
||
|
|
op->info.owner = (__u64) fl->fl_pid;
|
||
|
|
xop->callback = fl->fl_lmops->fl_grant;
|
||
|
|
locks_init_lock(&xop->flc);
|
||
|
|
locks_copy_lock(&xop->flc, fl);
|
||
|
|
xop->fl = fl;
|
||
|
|
xop->file = file;
|
||
|
|
} else {
|
||
|
|
op->info.owner = (__u64)(long) fl->fl_owner;
|
||
|
|
xop->callback = NULL;
|
||
|
|
}
|
||
|
|
|
||
|
|
send_op(op);
|
||
|
|
|
||
|
|
if (xop->callback == NULL)
|
||
|
|
wait_event(recv_wq, (op->done != 0));
|
||
|
|
else {
|
||
|
|
rv = FILE_LOCK_DEFERRED;
|
||
|
|
goto out;
|
||
|
|
}
|
||
|
|
|
||
|
|
spin_lock(&ops_lock);
|
||
|
|
if (!list_empty(&op->list)) {
|
||
|
|
log_error(ls, "dlm_posix_lock: op on list %llx",
|
||
|
|
(unsigned long long)number);
|
||
|
|
list_del(&op->list);
|
||
|
|
}
|
||
|
|
spin_unlock(&ops_lock);
|
||
|
|
|
||
|
|
rv = op->info.rv;
|
||
|
|
|
||
|
|
if (!rv) {
|
||
|
|
if (posix_lock_file_wait(file, fl) < 0)
|
||
|
|
log_error(ls, "dlm_posix_lock: vfs lock error %llx",
|
||
|
|
(unsigned long long)number);
|
||
|
|
}
|
||
|
|
|
||
|
|
kfree(xop);
|
||
|
|
out:
|
||
|
|
dlm_put_lockspace(ls);
|
||
|
|
return rv;
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL_GPL(dlm_posix_lock);
|
||
|
|
|
||
|
|
/* Returns failure iff a succesful lock operation should be canceled */
|
||
|
|
static int dlm_plock_callback(struct plock_op *op)
|
||
|
|
{
|
||
|
|
struct file *file;
|
||
|
|
struct file_lock *fl;
|
||
|
|
struct file_lock *flc;
|
||
|
|
int (*notify)(void *, void *, int) = NULL;
|
||
|
|
struct plock_xop *xop = (struct plock_xop *)op;
|
||
|
|
int rv = 0;
|
||
|
|
|
||
|
|
spin_lock(&ops_lock);
|
||
|
|
if (!list_empty(&op->list)) {
|
||
|
|
log_print("dlm_plock_callback: op on list %llx",
|
||
|
|
(unsigned long long)op->info.number);
|
||
|
|
list_del(&op->list);
|
||
|
|
}
|
||
|
|
spin_unlock(&ops_lock);
|
||
|
|
|
||
|
|
/* check if the following 2 are still valid or make a copy */
|
||
|
|
file = xop->file;
|
||
|
|
flc = &xop->flc;
|
||
|
|
fl = xop->fl;
|
||
|
|
notify = xop->callback;
|
||
|
|
|
||
|
|
if (op->info.rv) {
|
||
|
|
notify(fl, NULL, op->info.rv);
|
||
|
|
goto out;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* got fs lock; bookkeep locally as well: */
|
||
|
|
flc->fl_flags &= ~FL_SLEEP;
|
||
|
|
if (posix_lock_file(file, flc, NULL)) {
|
||
|
|
/*
|
||
|
|
* This can only happen in the case of kmalloc() failure.
|
||
|
|
* The filesystem's own lock is the authoritative lock,
|
||
|
|
* so a failure to get the lock locally is not a disaster.
|
||
|
|
* As long as the fs cannot reliably cancel locks (especially
|
||
|
|
* in a low-memory situation), we're better off ignoring
|
||
|
|
* this failure than trying to recover.
|
||
|
|
*/
|
||
|
|
log_print("dlm_plock_callback: vfs lock error %llx file %p fl %p",
|
||
|
|
(unsigned long long)op->info.number, file, fl);
|
||
|
|
}
|
||
|
|
|
||
|
|
rv = notify(fl, NULL, 0);
|
||
|
|
if (rv) {
|
||
|
|
/* XXX: We need to cancel the fs lock here: */
|
||
|
|
log_print("dlm_plock_callback: lock granted after lock request "
|
||
|
|
"failed; dangling lock!\n");
|
||
|
|
goto out;
|
||
|
|
}
|
||
|
|
|
||
|
|
out:
|
||
|
|
kfree(xop);
|
||
|
|
return rv;
|
||
|
|
}
|
||
|
|
|
||
|
|
int dlm_posix_unlock(dlm_lockspace_t *lockspace, u64 number, struct file *file,
|
||
|
|
struct file_lock *fl)
|
||
|
|
{
|
||
|
|
struct dlm_ls *ls;
|
||
|
|
struct plock_op *op;
|
||
|
|
int rv;
|
||
|
|
|
||
|
|
ls = dlm_find_lockspace_local(lockspace);
|
||
|
|
if (!ls)
|
||
|
|
return -EINVAL;
|
||
|
|
|
||
|
|
op = kzalloc(sizeof(*op), GFP_KERNEL);
|
||
|
|
if (!op) {
|
||
|
|
rv = -ENOMEM;
|
||
|
|
goto out;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (posix_lock_file_wait(file, fl) < 0)
|
||
|
|
log_error(ls, "dlm_posix_unlock: vfs unlock error %llx",
|
||
|
|
(unsigned long long)number);
|
||
|
|
|
||
|
|
op->info.optype = DLM_PLOCK_OP_UNLOCK;
|
||
|
|
op->info.pid = fl->fl_pid;
|
||
|
|
op->info.fsid = ls->ls_global_id;
|
||
|
|
op->info.number = number;
|
||
|
|
op->info.start = fl->fl_start;
|
||
|
|
op->info.end = fl->fl_end;
|
||
|
|
if (fl->fl_lmops && fl->fl_lmops->fl_grant)
|
||
|
|
op->info.owner = (__u64) fl->fl_pid;
|
||
|
|
else
|
||
|
|
op->info.owner = (__u64)(long) fl->fl_owner;
|
||
|
|
|
||
|
|
send_op(op);
|
||
|
|
wait_event(recv_wq, (op->done != 0));
|
||
|
|
|
||
|
|
spin_lock(&ops_lock);
|
||
|
|
if (!list_empty(&op->list)) {
|
||
|
|
log_error(ls, "dlm_posix_unlock: op on list %llx",
|
||
|
|
(unsigned long long)number);
|
||
|
|
list_del(&op->list);
|
||
|
|
}
|
||
|
|
spin_unlock(&ops_lock);
|
||
|
|
|
||
|
|
rv = op->info.rv;
|
||
|
|
|
||
|
|
if (rv == -ENOENT)
|
||
|
|
rv = 0;
|
||
|
|
|
||
|
|
kfree(op);
|
||
|
|
out:
|
||
|
|
dlm_put_lockspace(ls);
|
||
|
|
return rv;
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL_GPL(dlm_posix_unlock);
|
||
|
|
|
||
|
|
int dlm_posix_get(dlm_lockspace_t *lockspace, u64 number, struct file *file,
|
||
|
|
struct file_lock *fl)
|
||
|
|
{
|
||
|
|
struct dlm_ls *ls;
|
||
|
|
struct plock_op *op;
|
||
|
|
int rv;
|
||
|
|
|
||
|
|
ls = dlm_find_lockspace_local(lockspace);
|
||
|
|
if (!ls)
|
||
|
|
return -EINVAL;
|
||
|
|
|
||
|
|
op = kzalloc(sizeof(*op), GFP_KERNEL);
|
||
|
|
if (!op) {
|
||
|
|
rv = -ENOMEM;
|
||
|
|
goto out;
|
||
|
|
}
|
||
|
|
|
||
|
|
op->info.optype = DLM_PLOCK_OP_GET;
|
||
|
|
op->info.pid = fl->fl_pid;
|
||
|
|
op->info.ex = (fl->fl_type == F_WRLCK);
|
||
|
|
op->info.fsid = ls->ls_global_id;
|
||
|
|
op->info.number = number;
|
||
|
|
op->info.start = fl->fl_start;
|
||
|
|
op->info.end = fl->fl_end;
|
||
|
|
if (fl->fl_lmops && fl->fl_lmops->fl_grant)
|
||
|
|
op->info.owner = (__u64) fl->fl_pid;
|
||
|
|
else
|
||
|
|
op->info.owner = (__u64)(long) fl->fl_owner;
|
||
|
|
|
||
|
|
send_op(op);
|
||
|
|
wait_event(recv_wq, (op->done != 0));
|
||
|
|
|
||
|
|
spin_lock(&ops_lock);
|
||
|
|
if (!list_empty(&op->list)) {
|
||
|
|
log_error(ls, "dlm_posix_get: op on list %llx",
|
||
|
|
(unsigned long long)number);
|
||
|
|
list_del(&op->list);
|
||
|
|
}
|
||
|
|
spin_unlock(&ops_lock);
|
||
|
|
|
||
|
|
/* info.rv from userspace is 1 for conflict, 0 for no-conflict,
|
||
|
|
-ENOENT if there are no locks on the file */
|
||
|
|
|
||
|
|
rv = op->info.rv;
|
||
|
|
|
||
|
|
fl->fl_type = F_UNLCK;
|
||
|
|
if (rv == -ENOENT)
|
||
|
|
rv = 0;
|
||
|
|
else if (rv > 0) {
|
||
|
|
locks_init_lock(fl);
|
||
|
|
fl->fl_type = (op->info.ex) ? F_WRLCK : F_RDLCK;
|
||
|
|
fl->fl_flags = FL_POSIX;
|
||
|
|
fl->fl_pid = op->info.pid;
|
||
|
|
fl->fl_start = op->info.start;
|
||
|
|
fl->fl_end = op->info.end;
|
||
|
|
rv = 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
kfree(op);
|
||
|
|
out:
|
||
|
|
dlm_put_lockspace(ls);
|
||
|
|
return rv;
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL_GPL(dlm_posix_get);
|
||
|
|
|
||
|
|
/* a read copies out one plock request from the send list */
|
||
|
|
static ssize_t dev_read(struct file *file, char __user *u, size_t count,
|
||
|
|
loff_t *ppos)
|
||
|
|
{
|
||
|
|
struct dlm_plock_info info;
|
||
|
|
struct plock_op *op = NULL;
|
||
|
|
|
||
|
|
if (count < sizeof(info))
|
||
|
|
return -EINVAL;
|
||
|
|
|
||
|
|
spin_lock(&ops_lock);
|
||
|
|
if (!list_empty(&send_list)) {
|
||
|
|
op = list_entry(send_list.next, struct plock_op, list);
|
||
|
|
list_move(&op->list, &recv_list);
|
||
|
|
memcpy(&info, &op->info, sizeof(info));
|
||
|
|
}
|
||
|
|
spin_unlock(&ops_lock);
|
||
|
|
|
||
|
|
if (!op)
|
||
|
|
return -EAGAIN;
|
||
|
|
|
||
|
|
if (copy_to_user(u, &info, sizeof(info)))
|
||
|
|
return -EFAULT;
|
||
|
|
return sizeof(info);
|
||
|
|
}
|
||
|
|
|
||
|
|
/* a write copies in one plock result that should match a plock_op
|
||
|
|
on the recv list */
|
||
|
|
static ssize_t dev_write(struct file *file, const char __user *u, size_t count,
|
||
|
|
loff_t *ppos)
|
||
|
|
{
|
||
|
|
struct dlm_plock_info info;
|
||
|
|
struct plock_op *op;
|
||
|
|
int found = 0, do_callback = 0;
|
||
|
|
|
||
|
|
if (count != sizeof(info))
|
||
|
|
return -EINVAL;
|
||
|
|
|
||
|
|
if (copy_from_user(&info, u, sizeof(info)))
|
||
|
|
return -EFAULT;
|
||
|
|
|
||
|
|
if (check_version(&info))
|
||
|
|
return -EINVAL;
|
||
|
|
|
||
|
|
spin_lock(&ops_lock);
|
||
|
|
list_for_each_entry(op, &recv_list, list) {
|
||
|
|
if (op->info.fsid == info.fsid &&
|
||
|
|
op->info.number == info.number &&
|
||
|
|
op->info.owner == info.owner) {
|
||
|
|
struct plock_xop *xop = (struct plock_xop *)op;
|
||
|
|
list_del_init(&op->list);
|
||
|
|
memcpy(&op->info, &info, sizeof(info));
|
||
|
|
if (xop->callback)
|
||
|
|
do_callback = 1;
|
||
|
|
else
|
||
|
|
op->done = 1;
|
||
|
|
found = 1;
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
spin_unlock(&ops_lock);
|
||
|
|
|
||
|
|
if (found) {
|
||
|
|
if (do_callback)
|
||
|
|
dlm_plock_callback(op);
|
||
|
|
else
|
||
|
|
wake_up(&recv_wq);
|
||
|
|
} else
|
||
|
|
log_print("dev_write no op %x %llx", info.fsid,
|
||
|
|
(unsigned long long)info.number);
|
||
|
|
return count;
|
||
|
|
}
|
||
|
|
|
||
|
|
static unsigned int dev_poll(struct file *file, poll_table *wait)
|
||
|
|
{
|
||
|
|
unsigned int mask = 0;
|
||
|
|
|
||
|
|
poll_wait(file, &send_wq, wait);
|
||
|
|
|
||
|
|
spin_lock(&ops_lock);
|
||
|
|
if (!list_empty(&send_list))
|
||
|
|
mask = POLLIN | POLLRDNORM;
|
||
|
|
spin_unlock(&ops_lock);
|
||
|
|
|
||
|
|
return mask;
|
||
|
|
}
|
||
|
|
|
||
|
|
static const struct file_operations dev_fops = {
|
||
|
|
.read = dev_read,
|
||
|
|
.write = dev_write,
|
||
|
|
.poll = dev_poll,
|
||
|
|
.owner = THIS_MODULE
|
||
|
|
};
|
||
|
|
|
||
|
|
static struct miscdevice plock_dev_misc = {
|
||
|
|
.minor = MISC_DYNAMIC_MINOR,
|
||
|
|
.name = DLM_PLOCK_MISC_NAME,
|
||
|
|
.fops = &dev_fops
|
||
|
|
};
|
||
|
|
|
||
|
|
int dlm_plock_init(void)
|
||
|
|
{
|
||
|
|
int rv;
|
||
|
|
|
||
|
|
spin_lock_init(&ops_lock);
|
||
|
|
INIT_LIST_HEAD(&send_list);
|
||
|
|
INIT_LIST_HEAD(&recv_list);
|
||
|
|
init_waitqueue_head(&send_wq);
|
||
|
|
init_waitqueue_head(&recv_wq);
|
||
|
|
|
||
|
|
rv = misc_register(&plock_dev_misc);
|
||
|
|
if (rv)
|
||
|
|
log_print("dlm_plock_init: misc_register failed %d", rv);
|
||
|
|
return rv;
|
||
|
|
}
|
||
|
|
|
||
|
|
void dlm_plock_exit(void)
|
||
|
|
{
|
||
|
|
if (misc_deregister(&plock_dev_misc) < 0)
|
||
|
|
log_print("dlm_plock_exit: misc_deregister failed");
|
||
|
|
}
|
||
|
|
|